The present invention relates to a sheet ejection mechanism for allowing sheets on which images have been formed by a copier, printer, etc., to be ejected toward an out of the image-forming machine.
Generally, a sheet on which an image has been formed by a copier is ejected onto a sheet ejection tray while being maintained at the process speed of the copier.
In a high-speed machine involving a relatively high process speed, however, when a thicker sheet, etc., is ejected, ejection of the sheet from the sheet ejection tray has sometimes been encountered.
In a high-speed machine of such a type as to eject a sheet with an image-formed surface side inverted, even if a plain sheet of paper is involved, there are sometimes cases where, since at the ejection of the plain sheet the conveying speed of the sheet is faster than the process speed, ejection of the sheet from the sheet ejection tray occurs. In this sheet reverse turn type high-speed machine, when the plain sheet is switched back, the conveying speed of the sheet is made faster than the process speed, thus shortening a time required for a switch-back operation and avoiding a sheet-to-sheet collision at the switch-back section. When, therefore, the sheet is ejected at the same speed as an accelerated sheet conveying speed, then there are sometimes the cases where, even in the use of the plain sheet, the ejection of the sheet past the sheet ejection tray occurs.
If, in this way, a thin sheet, plain sheet, or the like is ejected past the sheet ejection tray, there occurs a problem that the sheet is soiled or torn. Even if the sheet is ejected onto the sheet ejection tray without being ejected, there are also cases where those ejected sheets are irregularly stacked on the sheet ejection tray.
The present invention is achieved with the above in view and the object of the present invention is to provide a sheet ejection mechanism that can eject sheets stably.
In order to achieve the above-mentioned object, a sheet ejection mechanism comprising: an ejection exit for allowing a sheet which is conveyed at a predetermined process speed through an image forming section to be ejected toward an outside of an image forming machine, the sheet having an image formed at least on one surface; a feeding mechanism for feeding the sheet, which is sent from the image forming section, at a first speed toward the ejection exit; and a speed reducing mechanism, provided near the ejection exit, for allowing the sheet which is sent by the feeding mechanism to be decelerated to a second speed lower than the first speed.
Further, a sheet ejection mechanism comprising: an ejection exit for allowing a sheet which is conveyed at a predetermined process speed through an image forming section to be ejected toward an outside of an image forming machine, the sheet having an image formed on one surface; a switch-back section for allowing the sheet which is sent from the image forming section to be conveyed at a first speed, the switch-back section turning a sheet conveying direction to a reverse direction to invert the sheet from one surface side to the other surface side; and a speed reducing mechanism, provided near the ejection exit, for allowing the sheet which is sent from the switch-back section to be decelerated to a second speed lower than the first speed and to be ejected via the ejection exit.
Still further, a sheet ejection mechanism comprising: an ejection exit for allowing a plurality of sheets which are conveyed at a predetermined conveying interval and at a predetermined process speed through an image forming section to be continuously ejected to an outside of an image forming machine, the respective sheet having an image formed on one surface; a switch-back section for allowing the respective sheets which are sent from the image forming section to be conveyed at a first speed and their conveying direction to be sequentially turned to a reverse direction to invert the sheet from one surface side to the other surface side; a speed reducing mechanism, provided near the ejection exit, for allowing the respective sheets which are, sent from the switch-back section to be decelerated to a second speed lower than the first speed and to be sequentially ejected via the ejection exit; and a control section for controlling the first speed to approximately the process speed when the conveying interval is longer than the length of the sheet along the conveying direction and the first speed to a higher speed than the process speed when the conveying interval is less than the length of the sheet along the conveying direction.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.